scholarly journals Mek and Cdc2 Kinase Are Sequentially Required for Golgi Disassembly in Mdck Cells by the Mitotic Xenopus Extracts

2000 ◽  
Vol 149 (2) ◽  
pp. 357-368 ◽  
Author(s):  
Fumi Kano ◽  
Katsuya Takenaka ◽  
Akitsugu Yamamoto ◽  
Kuniaki Nagayama ◽  
Eisuke Nishida ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Molecular Mechanisms ◽  
Mdck Cells ◽  
Morphological Changes ◽  
Green Fluorescence Protein ◽  
Membrane Dynamics ◽  
Mitogen Activated Protein Kinase ◽  
Golgi Membrane ◽  
Cdc2 Kinase ◽  
Electron Microscopies

At the onset of mitosis, the Golgi apparatus, which consists of several cisternae, disperses throughout the cell to be partitioned into daughter cells. The molecular mechanisms of this process are now beginning to be understood. To investigate the biochemical requirements and kinetics of mitotic Golgi membrane dynamics in polarized cells, we have reconstituted the disassembly of the Golgi apparatus by introducing Xenopus egg extracts into permeabilized Mardin-Darby canine kidney (MDCK) cells. We used green fluorescence protein (GFP)-tagged galactosyltransferase-expressing MDCK cells to analyze the morphological changes of the Golgi membrane in the semi-intact system. Analyses by fluorescence and electron microscopies showed that the Golgi disassembly can be dissected into two elementary processes morphologically. In the first process, the perinuclear Golgi stacks break into punctate structures, intermediates, which are comprised of mini-stacks of cisternae associating with apical microtubule networks. In the second process, the structures fragment more thoroughly or substantially relocate to the ER. Our analyses further showed that cdc2 kinase and mitogen-activated protein kinase kinase (MAPKK = MEK) are differently involved in these two processes: the first process is mainly regulated by MEK and the second mainly by cdc2.

scholarly journals Platelet-derived lysophosphatidic acid mediated LPAR1 activation as a therapeutic target for osteosarcoma metastasis

Oncogene ◽  
2021 ◽  
Author(s):  
Satoshi Takagi ◽  
Yuki Sasaki ◽  
Sumie Koike ◽  
Ai Takemoto ◽  
Yosuke Seto ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Pulmonary Metastasis ◽  
Lysophosphatidic Acid ◽  
Therapeutic Intervention ◽  
Molecular Mechanisms ◽  
Morphological Changes ◽  
Osteosarcoma Cells ◽  
Invasion And Metastasis ◽  
Platelet Releasate

AbstractOsteosarcoma is the most common primary malignant bone cancer, with high rates of pulmonary metastasis. Osteosarcoma patients with pulmonary metastasis have worse prognosis than those with localized disease, leading to dramatically reduced survival rates. Therefore, understanding the biological characteristics of metastatic osteosarcoma and the molecular mechanisms of invasion and metastasis of osteosarcoma cells will lead to the development of innovative therapeutic intervention for advanced osteosarcoma. Here, we identified that osteosarcoma cells commonly exhibit high platelet activation-inducing characteristics, and molecules released from activated platelets promote the invasiveness of osteosarcoma cells. Given that heat-denatured platelet releasate maintained the ability to promote osteosarcoma invasion, we focused on heat-tolerant molecules, such as lipid mediators in the platelet releasate. Osteosarcoma-induced platelet activation leads to abundant lysophosphatidic acid (LPA) release. Exposure to LPA or platelet releasate induced morphological changes and increased invasiveness of osteosarcoma cells. By analyzing publicly available transcriptome datasets and our in-house osteosarcoma patient-derived xenograft tumors, we found that LPA receptor 1 (LPAR1) is notably upregulated in osteosarcoma. LPAR1 gene KO in osteosarcoma cells abolished the platelet-mediated osteosarcoma invasion in vitro and the formation of early pulmonary metastatic foci in experimental pulmonary metastasis models. Of note, the pharmacological inhibition of LPAR1 by the orally available LPAR1 antagonist, ONO-7300243, prevented pulmonary metastasis of osteosarcoma in the mouse models. These results indicate that the LPA–LPAR1 axis is essential for the osteosarcoma invasion and metastasis, and targeting LPAR1 would be a promising therapeutic intervention for advanced osteosarcoma.

scholarly journals Beneficial Actions of Orostachys japonica and Its Compounds against Tumors via MAPK Signaling Pathways

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 555
Author(s):  
Soyoung Hur ◽  
Eungyeong Jang ◽  
Jang-Hoon Lee
Keyword(s):  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Malignant Tumors ◽  
Treatment Options ◽  
Underlying Mechanism ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Antitumor Effects ◽  
Mesenchymal Transition ◽  
Perennial Plant

Tumors are one of the most life-threatening diseases, and a variety of cancer treatment options have been continuously introduced in order to overcome cancer and improve conventional therapy. Orostachys japonica (O. japonica), which is a perennial plant belonging to the genus Orostachys of the Crassulaceae family, has been revealed to exhibit pharmacological properties against various tumors in numerous studies. The present review aimed to discuss the biological actions and underlying molecular mechanisms of O. japonica and its representative compounds—kaempferol and quercetin—against tumors. O. japonica reportedly has antiproliferative, anti-angiogenic, and antimetastatic activities against various types of malignant tumors through the induction of apoptosis and cell cycle arrest, a blockade of downstream vascular endothelial growth factor (VEGF)-VEGFR2 pathways, and the regulation of epithelial-to-mesenchymal transition. In addition, emerging studies have highlighted the antitumor efficacy of kaempferol and quercetin. Interestingly, it was found that alterations of the mitogen-activated protein kinase (MAPK) signaling cascades are involved in the pivotal mechanisms of the antitumor effects of O. japonica and its two compounds against cancer cell overgrowth, angiogenesis, and metastasis. In summary, O. japonica could be considered a preventive and therapeutic medicinal plant which exhibits antitumor actions by reversing altered patterns of MAPK cascades, and kaempferol and quercetin might be potential components that can contribute to the efficacy and underlying mechanism of O. japonica.

scholarly journals A Novel Golgi Membrane Protein Is a Partner of the ARF Exchange Factors Gea1p and Gea2p

2003 ◽  
Vol 14 (6) ◽  
pp. 2357-2371 ◽  
Author(s):  
Sophie Chantalat ◽  
Rëgis Courbeyrette ◽  
Francesca Senic-Matuglia ◽  
Catherine L. Jackson ◽  
Bruno Goud ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Protein Trafficking ◽  
Transmembrane Domain ◽  
Integral Membrane Protein ◽  
Membrane Dynamics ◽  
General Interest ◽  
Single Mutation ◽  
Golgi Membrane ◽  
Nucleotide Exchange

The Sec7 domain guanine nucleotide exchange factors (GEFs) for the GTPase ARF are highly conserved regulators of membrane dynamics and protein trafficking. The interactions of large ARF GEFs with cellular membranes for localization and/or activation are likely to participate in regulated recruitment of ARF and effectors. However, these interactions remain largely unknown. Here we characterize Gmh1p, the first Golgi transmembrane-domain partner of any of the high-molecular-weight ARF-GEFs. Gmh1p is an evolutionarily conserved protein. We demonstrate molecular interaction between the yeast Gmh1p and the large ARF-GEFs Gea1p and Gea2p. This interaction involves a domain of Gea1p and Gea2p that is conserved in the eukaryotic orthologues of the Gea proteins. A single mutation in a conserved amino acid residue of this domain is sufficient to abrogate the interaction, whereas the overexpression of Gmh1p can compensate in vivo defects caused by mutations in this domain. We show that Gmh1p is an integral membrane protein that localizes to the early Golgi in yeast and in human HeLa cells and cycles through the ER. Hence, we propose that Gmh1p acts as a positive Golgi-membrane partner for Gea function. These results are of general interest given the evolutionary conservation of both ARF-GEFs and the Gmh proteins.

scholarly journals When nutrition interacts with osteoblast function: molecular mechanisms of polyphenols

2009 ◽  
Vol 22 (1) ◽  
pp. 68-81 ◽  
Author(s):  
Anna Trzeciakiewicz ◽  
Véronique Habauzit ◽  
Marie-Noëlle Horcajada
Keyword(s):  
Bone Health ◽  
Molecular Mechanisms ◽  
Vegetable Intake ◽  
Cell Metabolism ◽  
Bone Cell ◽  
Mitogen Activated Protein Kinase ◽  
Present Review ◽  
Activator Protein 1 ◽  
Cellular Signalling ◽  
Osteoblast Function

Recent research has provided insights into dietary components that may optimise bone health and stimulate bone formation. Fruit and vegetable intake, as well as grains and other plant-derived food, have been linked to decreased risk of major chronic diseases including osteoporosis. This effect has been partially attributed to the polyphenols found in these foods. Thus, it has been suggested that these compounds may provide desirable bone health benefits through an action on bone cell metabolism. The present review will focus on how some polyphenols can modulate osteoblast function and reports which cellular signalling pathways are potentially implicated. However, to date, despite numerous investigations, few studies have provided clear evidence that phenolic compounds can act on osteoblasts. Polyphenols cited in the present review seem to be able to modulate the expression of transcription factors such as runt-related transcription factor-2 (Runx2) and Osterix, NF-κB and activator protein-1 (AP-1). It appears that polyphenols may act on cellular signalling such as mitogen-activated protein kinase (MAPK), bone morphogenetic protein (BMP), oestrogen receptor and osteoprotegerin/receptor activator of NF-κB ligand (OPG/RANKL) and thus may affect osteoblast functions. However, it is also important to take in account the possible interaction of these compounds on osteoclast metabolism to better understand the positive correlation reported between the consumption of fruit and vegetables and bone mass.

Docosahexaenoic Acid, a Peroxisome Proliferator-Activated Receptor-α Activator, Induces Apoptosis in Vascular Smooth Muscle Cells by Activation of P38 Mitogen-Activated Protein Kinase

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 679-679
Author(s):  
Quy N Diep ◽  
Rhian M Touyz ◽  
Ernesto L Schiffrin
Keyword(s):  
Smooth Muscle ◽  
Cytochrome C ◽  
Docosahexaenoic Acid ◽  
Vascular Smooth Muscle ◽  
Morphological Changes ◽  
Mitogen Activated Protein Kinase ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Mitogen Activated Protein ◽  
P38 Mapks

9 Omega-3 fatty acids (n-3 FAs) exert a blood pressure-lowering effect in hypertension, possibly by influencing vascular structure. We previously demonstrated that n-3 FAs might induce vascular smooth muscle cell (VSMC) apoptosis, which could exert an effect on structure of blood vessels. This study investigated signaling pathways through which n-3 FAs mediate apoptosis in VSMCs. Cultured Mesenteric VSMCs from Sprague Dawley rats were stimulated with docosahexaenoic acid (DHA), a representative n-3 FA. Morphological changes of apoptosis and DNA fragmentation were examined by phase-contrast microscopy and fluorescence microscopy with Hoechst 33342 staining. To clarify possible pathways of apoptosis, expression of phosphorylated p38 mitogen-activated protein kinases (p38 MAPKs), bax, bcl-2, cytochrome C and peroxisome proliferator-activated receptors-α (PPARs-α) was evaluated by Western blot analysis. DHA treatment induced cell shrinkage, cell membrane blebbing and apoptotic bodies in VSMCs. DHA increased apoptosis (%) in a time-dependent manner to 1.5±0.1, 3.6±0.5, 7.1±0.4, 22.5±0.6, 50.8±1.8 and 61.4±0.9 after 0, 1, 3, 6, 17, and 24 h, respectively. DHA time-dependently activated p38 MAPKs, bax, PPARs-α and cytochrome C with maximal effects obtained after 5, 30 min, 1 h and 3 h, respectively to 551±42, 245±55, 310±12 and 407±14.7 % of controls, respectively. SB-203580 (10 -5 M) and SB-202190 (10 -5 M), selective p38 inhibitors, reduced DHA-elicited apoptosis and expression of PPARs-α, but had no effect on expression of bax or cytochrome C. The present results indicate that DHA induces apoptosis in VSMCs through at least two distinct mechanisms: (i) a p38-dependent pathway that regulates PPAR-α and (ii) a p38-independent pathway via dissipation of mitochondrial transmembrane potential. The death-signaling pathway mediated by DHA may involve an integration of these multiple pathways. By triggering VSMC apoptosis, DHA could play a pathophysiological role in vascular remodeling in cardiovascular disease.

The Action of Diethylstilboestrol on the Prostatic Epithelium of the Mouse

1947 ◽  
Vol s3-88 (1) ◽  
pp. 45-53
Author(s):  
E. S. HORNING
Keyword(s):  
Golgi Apparatus ◽  
Inbred Strain ◽  
Normal Condition ◽  
Morphological Changes ◽  
Anterior Lobe ◽  
Cellular Changes ◽  
Prostatic Epithelium

1. The cellular changes in the prostatic epithelium of an inbred strain of mice (R III), following short periods of treatment with large doses of oestrogen, are described. 2. The Golgi apparatus in the cells of the prostatic epithelium affords a precise indication of the degree of stimulation induced by oestrogenic substances. 3. Specific morphological changes in the Golgi substance occur in the epithelium of the anterior lobe of the prostate after 8 days' treatment. Similar changes, following longer periods of treatment, also occur in the dorsal and ventral lobes. 4. Withdrawal of oestrogenic stimulation after 20 days' treatment with relatively large doses is followed by a return of the prostatic epithelium and the Golgi apparatus to their normal condition in 21 days.

Cadmium is more toxic to LLC-PK1cells than to MDCK cells acting on the cadherin-catenin complex

1998 ◽  
Vol 275 (1) ◽  
pp. F143-F153 ◽  
Author(s):  
L. B. Zimmerhackl ◽  
F. Momm ◽  
G. Wiegele ◽  
M. Brandis
Keyword(s):  
Mdck Cells ◽  
Morphological Changes ◽  
Collecting Duct ◽  
Cadmium Toxicity ◽  
Distal Tubule ◽  
Insoluble Fraction ◽  
Atp Depletion ◽  
Rhodamine Phalloidin ◽  
Apical Side ◽  
E Cadherin

Cadmium toxicity to renal cells was investigated in Madin-Darby canine kidney (MDCK) and LLC-PK1cells as models of the distal tubule/collecting duct and proximal tubule, respectively. Cells were grown on two-compartment filters and exposed to 0.1–50 μM Cd2+. In MDCK cells, Cd2+was more toxic from the basolateral than from the apical side and dependent on the extracellular Ca2+concentration. Toxicity was evident within 24 h, as shown by a decrease in transepithelial resistance (TER), reduced proliferation (bromodeoxyuridine incorporation), reduction in ATP concentration, and morphological changes. On confocal microscopy, E-cadherin and α-catenin staining patterns indicated interference with the cadherin-catenin complex. LLC-PK1cells showed a similar toxicity pattern, which was evident at lower Cd2+concentrations. An increase of E-cadherin and α-catenin molecules in the Triton X-100-insoluble fraction was detectable at high Cd2+concentrations in LLC-PK1cells but not in MDCK cells. Lactate dehydrogenase release indicated membrane leakage in LLC-PK1cells. Rhodamine-phalloidin staining, a probe for F-actin filaments, demonstrated alterations of the actin cytoskeleton in both cell lines. In conclusion, cadmium caused ATP depletion and interfered with the cadherin-catenin complex and probably the tight junctions changing renal cell morphology and function.

scholarly journals The TGFβ-induced phosphorylation and activation of p38 mitogen-activated protein kinase is mediated by MAP3K4 and MAP3K10 but not TAK1

Open Biology ◽  
2013 ◽  
Vol 3 (6) ◽  
pp. 130067 ◽  
Author(s):  
Gopal P. Sapkota
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Transforming Growth Factor Beta ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Phosphorylation ◽  
Mesenchymal Transition ◽  
Mitogen Activated Protein

The signalling pathways downstream of the transforming growth factor beta (TGFβ) family of cytokines play critical roles in all aspects of cellular homeostasis. The phosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) has been implicated in TGFβ-induced epithelial-to-mesenchymal transition and apoptosis. The precise molecular mechanisms by which TGFβ cytokines induce the phosphorylation and activation of p38 MAPK are unclear. In this study, I demonstrate that TGFβ-activated kinase 1 (TAK1/MAP3K7) does not play a role in the TGFβ-induced phosphorylation and activation of p38 MAPK in MEFs and HaCaT keratinocytes. Instead, RNAi -mediated depletion of MAP3K4 and MAP3K10 results in the inhibition of the TGFβ-induced p38 MAPK phosphorylation. Furthermore, the depletion of MAP3K10 from cells homozygously knocked-in with a catalytically inactive mutant of MAP3K4 completely abolishes the TGFβ-induced phosphorylation of p38 MAPK, implying that among MAP3Ks, MAP3K4 and MAP3K10 are sufficient for mediating the TGFβ-induced activation of p38 MAPK.

Alternation of Mitochondrial and Golgi Apparatus in Neurodegenerative Disorders

2019 ◽  
pp. 102-128
Author(s):  
Sonia Sharma ◽  
Paramjeet Kaur ◽  
Shallina Gupta ◽  
Sushant Sharma
Keyword(s):  
Golgi Apparatus ◽  
Neurodegenerative Disorders ◽  
Morphological Changes ◽  
Mitochondrial Dysfunctions ◽  
Over Expression ◽  
Associated Proteins ◽  
Environmental Causes ◽  
Altered Proteins ◽  
Lateral Sclerosis ◽  
Apoptotic Factors

Neurodegenerative disorders (NDs) are characterized by dysfunction and loss of neurons associated with altered proteins that accumulate in the human brain and peripheral organs. Mitochondrial and Golgi apparatus (GA) dysfunctions are supposed to be responsible for various NDs. Damaged mitochondria do not produce sufficient adenosine triphosphate (ATP) and produce reactive oxygen species (ROS) and pro-apoptotic factors. Mitochondrial dysfunctions may be caused by various factors such as environmental causes, mutations in both nuclear or mitochondrial deoxyribonucleic acid (DNA), that code many mitochondrial components. Three factors that are mainly responsible for the morphological changes in GA are certain pathological conditions, drugs, and over expression of Golgi associated proteins. In this chapter, common aspects of mitochondrial and GA dysfunction concerned about NDs are summarized and described for Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD).

Membrane dynamics in relation to fluid absorption in reptilian proximal renal tubules

1989 ◽  
Vol 257 (5) ◽  
pp. R982-R988
Author(s):  
W. H. Dantzler
Keyword(s):  
Cell Volume ◽  
Morphological Changes ◽  
Apical Cell ◽  
Volume Ratio ◽  
Membrane Dynamics ◽  
Renal Tubules ◽  
Fluid Absorption ◽  
Bathing Medium ◽  
Membrane Area ◽  
Permissive Role

Net fluid absorption (Jv), cell volume, and cell membrane area have been studied in isolated, perfused snake (Thamnophis spp.) proximal tubules. With Na+ in both perfusate and bathing medium, Jv averages approximately 0.9 nl.min-1.mm-1. When choline replaces Na+ in perfusate, Jv nearly ceases. When choline also replaces Na+ in bathing medium, so that both solutions are identical, Jv returns to the control rate. The results are the same when tetramethylammonium replaces Na+, when sucrose replaces Na+ and the equivalent amount of Cl-, and when methyl sulfate replaces Cl- alone. However, when Li+ replaces Na+ in perfusate alone or in both perfusate and bathing medium, Jv is unchanged. Jv at control rates is isosmotic and can be partially inhibited by cold and cyanide. When choline replaces Na+ in perfusate and bathing medium, cell volume doubles, and intercellular space volume nearly quintuples. The areas of the lateral and apical cell membranes also approximately double, so that the surface area-to-volume ratio remains constant. These morphological changes in the absence of Na+ occur concomitantly with maintenance of Jv, suggesting that they may play a permissive role in such maintenance.

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